1. Field of the Invention
The present invention relates to a reinforced support structure for supporting a display panel, a panel display device supported by the support structure and having a supporting member, and an image forming apparatus using the panel display device.
2. Related Background Art
A flat plane image forming apparatus has been used for the image display on televisions and computers, advertisement media, sign boards and the like. Flat plane image forming apparatuses include those image forming apparatuses using a display panel using electron emitting elements, a display panel using plasma discharge, a display panel using liquid crystal, and the like. A wall hanging type, a wall embedded type, a desktop type, a floor type and the like are known as display panel mount types.
An example of a conventional mount structure for an image forming apparatus with a display panel using plasma discharge is shown in FIG. 6. The main components of this structure are constituted of: a front cover (bezel) 81 for protecting a display panel 82 using plasma discharge; a flexible flat cable 83 for transferring electrical signals to the display panel; a chassis 84 for supporting the display panel, the chassis being made of iron-based material and formed through sheet plate work; mount members 85 for mounting the front cover 81, the mount members being formed at the peripheral area of the chassis; screw threading members 86 for fixing an electronic component mounting board 87, the screw threading members being formed through cutting and bending the chassis 84 and the electronic component mounting board 87 being used for processing externally input electrical signals and supplying them to the display panel; a rear cover 89 having a reinforcing plate 88 for mounting the image forming apparatus on an external wall hanger or desktop stand (not shown); and a cable 90 for electrical connection of the electronic component mounting board 87 to an external power source and tuner (not shown).
FIG. 7 is an enlarged cross sectional view showing a partial area of the image forming apparatus shown in FIG. 6. In FIG. 7, a pit inserting screw 85-a and a boss 85-b of the front cover 81 into which the screw is inserted, are illustrated.
The detailed descriptions of the function and aspects of this mount structure will be further given. The display panel 82 is made of two glass substrates adhered together with a space being provided therebetween. This space is filled with specific rare gas and thereafter hermetically sealed. The inner surfaces of the opposing two glass substrates are formed with an electrode film, an insulating film, a fluorescent film, and a shielding film. Electrical signals supplied from the electronic component mounting board 87 via the flexible flat cable 83 are applied to the electrode film (X, Y matrix patterns) to drive a pixel element. As a predetermined voltage is applied to the pixel element, rare gas near the pixel element emits ultraviolet rays which excite the fluorescent film to emit light. Each pixel of the fluorescent film is divided into red, green and blue areas in chromaticity to thereby realize a color image.
The chassis 84 is used for supporting the display panel 82 in the housing of the image processing apparatus, the chassis 84 and display panel 82 being fixed together by using a both-side adhesive tape (not shown). The material of the chassis 84 is made of a rigid metal plate (such as a galvanized steel sheet) in order to reliably support the display panel 82. The mount members 85 with a small through hole are provided at the peripheral area of the chassis 84 in order to mount the front cover 81 by using the screws 85-a threaded into the bosses 85-b of the front cover 81. On the back side of the chassis 84, the screw threading members 86 with a screw hole 86 are provided in order to mount the electronic component mounting board 87 by using screws.
On the inner side of the rear cover 89, the reinforcing plate 88 is fixed in order to mount the image forming apparatus on an external wall hanger or desktop stand by using screws which are threaded into the reinforcing plate 88.
The invention provides a novel panel support structure.
According to one aspect of the present invention, a panel support structure for supporting a panel for displaying an image is provided, which comprises a holding member for holding the panel which astride an edge of the panel.
With this structure, the panel is supported at peripheral two contrary surfaces thereof. Therefore, even if there is a size error or change between the panel and the support structure, it is still possible to support the panel. For example, the panel can be supported even if expansion or contraction by a temperature change (an ambient temperature change or a temperature change caused by a heat generation change of the panel) affects the size error or change. In this case, a substantial overlap amount between the holding member and the two contrary surfaces of the panel is determined under consideration of the degrees of thermal expansions of the panel and the panel support structure. The substantial overlap amount is, for example, an overlap amount between a damper and the surface of the panel, if the panel support structure holds the panel by using the holding member, with the damper to be described later being interposed therebetween.
The holding member may be provided at the four corners of the panel. A deflection of the panel can be suppressed more reliably if a holding portion is provided not only at the corner of the panel but also at the whole side of the panel or at a plurality of positions of the panel. It is not necessary to provide the holding portion at all the four sides. It is however preferable to provide the holding portion at least at the opposing two sides of the panel.
With this structure, a plurality of holding members may be provided to support the panel at a plurality of positions and to couple the holding members to a supporting member. The holding member and the supporting member may be formed integrally or separately.
The holding member may be provided with a damper at a position where the panel becomes or possibly becomes in contact with the holding member. The damper may be made of rubber. The rubber hardness is preferably 50 (JIS-A) or higher.
It is preferable to use as the material of the supporting member a material other than glass, such as metal.
If the supporting member is made of a rod-like member, the weight thereof can be reduced. Wherein, rod-like member includes an elongated plate member. The supporting member may be a combination of a rod-like members and a plate member. It is preferable that a length of the rod-like member along a longitudinal direction is longer than a length of a longer side of the panel. A plurality of rod-like members may be used. The rod-like members may be crossed each other. For example, the rod-like members are disposed in an X-character shape. If the rod-like members are crossed each other, it is preferable that they are fixed at the cross points. The supporting member with the cross points may be formed integrally or separately. The rod-like member has a rectangular or circular cross section. It is preferable that a length of the cross section of the rod-like member along a thickness direction of the panel is longer than a length of the cross section along a direction parallel to a surface of the panel. While it may be reversed, when the supporting structure is to be thinner. It is also preferable (in the earlier case) that a length of the cross section of the rod-like member along a thickness direction of the panel is 1/80 or longer than a diagonal line of the panel.
The thermal conduction of the panel differs at respective positions where it is in contact with the supporting member or not in contact. If a difference of the thermal conductivity may pose some practical problem, it is preferable that the supporting member is made in contact with the panel only at a portion of the supporting member or not in contact with the panel. A heat insulating member or a protective buffer may be inserted between the panel and the supporting member.
According to another aspect of the present invention, a panel support structure for supporting a panel for displaying an image is provided which comprises a supporting member having a rod-like member made of a material different from a material of the panel, wherein a length of the rod-like member along a longitudinal direction is longer than a length of a longer side of the panel.
This panel support structure may take various configurations similar to the holding member. As described earlier, the panel may be supported at its corner or at its side.
As the material of the supporting member, metal may be used if the panel is made of glass. A plurality of rod-like members may be used. The rod-like members may be crossed each other. For example, the rod-like members are disposed in an X-character shape. If the rod-like members are crossed each other, it is preferable that they are fixed at the cross points. The supporting member with the cross points may be formed integrally or separately. The rod-like member has a rectangular or circular cross section. In this case, it is preferable that a length of the cross section of the rod-like member along a thickness direction of the panel is longer than a length of the cross section along a direction parallel to a surface of the panel. It may be reversed, when supporting structure is to be thinner. It is also preferable (in the earlier case) that a length of the cross section of the rod-like member along a thickness direction of the panel is 1/80 or longer than a diagonal line of the panel (particularly when the rod-like members are disposed along diagonal lines of the panel).
The thermal conduction of the panel differs at respective positions where it is in contact with the supporting member or not in contact. If a difference of the thermal conductivity may pose some practical problem, it is preferable that the supporting member is made in contact with the panel only at a portion of the supporting member or not in contact with the panel. A heat insulating member or a protective buffer may be inserted between the panel and the supporting member.
The panel support structure according to each of the aspects of the present invention may have the following configurations.
The panel support structure may be used as an electrical ground. For example, the panel support structure may have a mount portion for mounting a cover which accommodates at least a portion of a panel display device including the panel and the panel support structure. In this case, if the inner surface of the cover is made conductive by coating a conductive film on the inner surface through plating or painting, the cover and the panel support structure may be electrically connected at the mount portion to ground the cover.
The panel support structure may be partially provided with a mount portion for mounting a circuit board for controlling or driving the panel. A ground level wiring line (pattern) of the circuit board may be connected to the panel support structure via the mount portion.
If the panel support structure and the cover are made in contact with each other on flat surfaces, the reliability of the electrical connection can be improved. As a means for mechanically coupling the panel support structure to the cover, screws may be used. Similarly, if the panel support structure and the circuit board are made in contact with each other on flat surfaces, the reliability of the electrical connection can be improved. Also, as a means for mechanically coupling the panel support structure and the cover, screws may be used.
An installing member such as a desktop stand or wall hanger is sometimes used for installing a panel display device including the panel and panel support structure. In this case, it is preferable that the panel support structure has a mount portion for mounting the installing member. If the mount portion is provided near at an end of the panel display device, the panel device can be installed more stably. If the mount portion is provided near at a center of the panel or the center of gravity of the panel, it becomes easy to adjust the direction and angle of the panel display is device and the display screen becomes hard to be fluctuated by external vibrations.
The invention also includes the following configurations.
A panel support structure for supporting a panel for displaying an image which comprises a mount portion for mounting an installing member for installing a panel device including the panel and the panel support structure.
A panel support structure for supporting a panel for displaying an image wherein at least a portion of the panel support structure is conductive and electrically grounded.
The invention also includes a panel display having the panel and the panel support structure described above.
The invention also includes an image forming apparatus using the panel display device.
The present invention can solve at least some of the following problems which the panel support structure shown in FIG. 6 cannot solve.
1. The chassis 84 for supporting the display panel 82 in the housing of the flat plane type image forming apparatus is generally made of an iron-based plate formed through sheet plate work. Therefore, the weight of the image forming apparatus increases and transportation thereof becomes difficult, or it becomes necessary to reinforce a wall itself on which the wall hanger is mounted.
2. Since the materials of the display panel 82 and chassis 84 are different, a difference between the sizes of these two devices becomes large as an ambient temperature changes so that the display panel 82 may be deformed and the display performance thereof may be degraded.
3. In order to suppress electromagnetic radiation noises to be generated from the display panel 82 and electronic component mounting board 87, it is necessary to form a conductive film on the surfaces of the front cover 81 and rear cover 89 and electrically ground the conductive films. In this context, however, when the pit inserting screw 85-a is heated and inserted into the boss 85-b of the front cover 81, resin of the material of the front cover is melted and the flat surface of the boss 85-b is formed with a swelled resin region which unstabilizes the surface contact with the screw mounting member of the chassis 85. Therefore, leakage of electromagnetic radiation noises may occur.
4. Under the condition that the flat plane image forming apparatus is mounted on the external wall hanger or desktop stand, the reinforcing plate 88 supports the heavy display panel 82 and chassis 84 via the rear and front covers. Therefore, when a user wants to change the direction of the display screen, it is not easy to fix the direction because of this mount structure or because the display screen may fluctuate when there is a vibration even if it is small.
5. Heat generated by the display panel 82 directly transmits to the chassis 84 and thermally affects the electronic component mounting board 87, or conversely, heat generated by the electronic component mounting board 87 thermally affects the display panel 82 via the chassis 84. Therefore, the display performance of the display panel 82 may be deteriorated or the electrical characteristics of the electronic component mounting board 87 may be affected.
6. Since the power source and tuner are not built in the flat plane type image forming apparatus mounted on the wall, another mount space for the power source and tuner is required and the cable 90 is required to be connected to the power source and tuner. Therefore, the mount site of the flat plane type image forming apparatus is limited to particular areas.
7. Since the both-side adhesive tape is used for adhering the display panel 82 and chassis 84, materials of the apparatus are difficult to be separated when the apparatus is dumped.